subject: legal environment in business.

please answer full question and in bangladesh prospective.

2. (a) How may an offer be terminated ? (Pages 26-28) (b) A offers to sell B his horse for Rs. 1000 and tells B. 'This offer will remain open one week'. The following day B reject the offer. Within the week B changes his mind and notifies A that he accepts the offer. Is there a contract ? (Para 6, Page 30)